title: Elongation factor-1α is a novel protein associated with host cell invasion and a potential protective antigen of Cryptosporidium parvum.
abstract: The phylum Apicomplexa comprises obligate intracellular parasites that infect vertebrates. All invasive forms of Apicomplexa possess an apical complex, a unique assembly of organelles localized to the anterior end of the cell and involved in host cell invasion. Previously, we generated a chicken monoclonal antibody (mAb), 6D-12-G10, with specificity for an antigen located in the apical cytoskeleton of Eimeria acervulina sporozoites. This antigen was highly conserved among Apicomplexan parasites, including other Eimeria spp., Toxoplasma, Neospora, and Cryptosporidium. In the present study, we identified the apical cytoskeletal antigen of Cryptosporidium parvum (C. parvum) and further characterized this antigen in C. parvum to assess its potential as a target molecule against cryptosporidiosis. Indirect immunofluorescence demonstrated that the reactivity of 6D-12-G10 with C. parvum sporozoites was similar to those of anti-β- and anti-γ-tubulins antibodies. Immunoelectron microscopy with the 6D-12-G10 mAb detected the antigen both on the sporozoite surface and underneath the inner membrane at the apical region of zoites. The 6D-12-G10 mAb significantly inhibited in vitro host cell invasion by C. parvum. MALDI-TOF/MS and LC-MS/MS analysis of tryptic peptides revealed that the mAb 6D-12-G10 target antigen was elongation factor-1α (EF-1α). These results indicate that C. parvum EF-1α plays an essential role in mediating host cell entry by the parasite and, as such, could be a candidate vaccine antigen against cryptosporidiosis.
authors.affiliation: Department of Food and Nutrition, Osaka Yuhigaoka Gakuen Junior College, Tennoji-ku, Osaka 543-0073, Japan; Bacterial and Parasitic Disease Research Division, National Institute of Animal Health, National Agricultural and Food Research Organization, Tsukuba, Ibaraki 305-0856, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsubayashi
authors.affiliation: Department of Parasitology, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka 545-8585, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Teramoto-Kimata
authors.affiliation: Department of Parasitology, Graduate School of Medicine, Osaka City University, Abeno-ku, Osaka 545-8585, Japan; Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Uni
authors.affiliation: United States Department of Agriculture, Animal Biosciences and Biotechnology Laboratory, Beltsville Agricultural Research Center, Beltsville, Maryland 20705.
authors.forename: Hyun S
authors.initials: HS
authors.lastname: Lillehoj
authors.affiliation: Laboratory of Immunobiology, Department of Molecular and Applied Biosciences, Graduate School of Biosphere Sciences, Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8528, Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Matsuda
authors.affiliation: Department of Veterinary Internal Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka 598-8531, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Furuya
authors.affiliation: Department of Veterinary Internal Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka 598-8531, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tani
authors.affiliation: Department of Veterinary Internal Medicine, Division of Veterinary Science, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Izumisano, Osaka 598-8531, Japan. Electronic address: ksasai@vet.osakafu-u.ac.jp.
authors.forename: Kazumi
authors.initials: K
authors.lastname: Sasai
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000276:immunology / Q000378:metabolism; D003457:Cryptosporidiosis / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000517:prevention & control; D016785:Cryptosporidium parvum / Q000276:immunology* / Q000378:metabolism / Q000472:pathogenicity; D008297:Male; D051379:Mice; D016513:Mice, SCID; D020648:Peptide Elongation Factor 1 / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D016052:Protozoan Vaccines / Q000276:immunology; D034101:Sporozoites / Q000276:immunology* / Q000378:metabolism
chemical_list: D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D020648:Peptide Elongation Factor 1; D015800:Protozoan Proteins; D016052:Protozoan Vaccines
keywords: Cell-penetrating Peptides; Cytoskeleton; Electron Microscopy (EM); Protozoan; Transcription Elongation Factors; Translation Elongation Factors; Western Blotting